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Accuracy and Precision- The Test

To understand any of this you need to read parts one and two. There I laid out what we are trying to accomplish and why.

The short
version is using testing to find where the gaps are in your equipment. For this
example I am attempting to find the inherent accuracy of a rifle and ammunition
combination.

Here is how it would be combined. For this test, four groups of 5 rounds from with 2 minutes between groups are recorded and averaged.

Sample A

Ammo A

Group size: 0.85 MOA average.

SD: 8

Mantis
Score: (Benched) 99.1

Ammunition B.

Sample B

Group size: 1.24 MOA

SD: 27
Mantis Score: 99.5

From this example, we can see that Ammo B had some issues. Despite less movement in the rifle, the group size got larger, most likely due to the ammunition.

While this isn’t enough to make a conclusion on, we know that ammo B is a no go for what we need. We have not yet worked on rifle or optic choice.

Rifle with Ammunition A is now our control.

Adding a
shooter to the mix now makes it look like this (Rifle with Ammo A)

Group Size:
1.5 MOA Average

SD 8

Mantis
Score: 97.5

We see an increase in group size and a lower Mantis X score. We know everything above .85 MOA is shooter induced. If the shooter has been using Mantis and his average is 97.5 dry and live, we can now look at things to improve the shooter’s interaction with the firearm.

The first thing people talk about is a trigger so let’s work those

Control:
97.5

A: 99

B: 91

Without
firing a live round, we can now see that adding Trigger A into the rifle will
perhaps bring us closer to the control rifle numbers.

Rifle with
Ammo and Trigger A

Group Size:
.97 MOA

Mantis
Score: 99

We can also
go back through all this data to see the abnormalities. If we took notes and
tracked things like lighting conditions and wind, we may see that as the light
changed our shooters groups got larger and with complaints of targets are harder
to see. By looking for an optic with more light transmission, we may gain a bit
in other conditions.

What we did
make was two informed, performance-based decisions. We chose an ammunition and
a trigger that got us closer to the goal. With more ammunition testing we may
find a load with SD’s in the 3s that gets us .6 MOA groups with the same rifle.
That may put our shooter into the .7 MOA area.

Notice I never mentioned a brand or a price. It was all actual performance of the rifle, ammo, and shooter. We are human after all and individuals. Something that works well for me may not for you. What I challenge you to do is get smart, collect data, make informed decisions and be happy with choices.

This series has been on finding accuracy. From here we will go into precision.

I am also a Retired US Army Senior NCO. My last assignments included serving as the Senior Writer for Small Arms in the Weapons and Gunnery Branch and the US Army Infantry School Marksmanship Program developer at the Maneuver Center of Excellence Fort Benning, Georgia.